This following pertains generally to the field of circuits for the determination of a temperature code and, more particularly, to techniques for improving the efficiency of their operation and calibration.
The various components of an integrated circuit often behave differently at different temperatures. Because of this, operating parameters on the circuit are often adjusted based on the temperature. This requires a determination of the temperature and, for this purpose, the circuit may include a circuit for determining a parameter indicative of the temperature, or temperature code, that is then used to set these operating parameters. The temperature code (TCO) typically provides a multi-bit digital value that is then used to set the relative parameters. For example, in the case of a non-volatile memory circuitry, various sensing parameters used in read and verify operations are often adjusted based on a temperature code. Although these circuits are typically trimmed to be accurate when a device is initial set up, they will usually need to be calibrated before generating the temperature code in order to ensure accuracy. Considering the memory circuit example again, when the circuit receives a read request, the temperature code circuit would first be calibrated, then the code generated, after which the code is provided to state machine to select the appropriate sensing parameters. The need to perform the separate calibration operation can slow down the process.